diff mbox

[3/4] tmp: factor out tpm1_get_random into tpm1-cmd.c

Message ID 20180306093041.11996-4-tomas.winkler@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Winkler, Tomas March 6, 2018, 9:30 a.m. UTC 
Factor out get random implementation from tpm-interface.c
into tpm1_get_random function in tpm1-cmd.c.
No functional changes.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
 drivers/char/tpm/tpm-interface.c | 56 ++++------------------------------------
 drivers/char/tpm/tpm.h           |  2 ++
 drivers/char/tpm/tpm1-cmd.c      | 54 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 51 deletions(-)

Comments

Jarkko Sakkinen March 6, 2018, 11:31 a.m. UTC | #1 
On Tue, 2018-03-06 at 11:30 +0200, Tomas Winkler wrote:
> Factor out get random implementation from tpm-interface.c
> into tpm1_get_random function in tpm1-cmd.c.
> No functional changes.
> 
> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>

While you are doing this, please make it use tpm_buf so tha we get stuff
out of that nasty union. Using "helper" structs is still fine, just move
it right before the function implementation out of tpm.h (there are
examples of this tpm2-cmd.c).

/Jarkko
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Winkler, Tomas March 6, 2018, 11:34 a.m. UTC | #2 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--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Jarkko Sakkinen March 6, 2018, 1:56 p.m. UTC | #3 
On Tue, Mar 06, 2018 at 11:34:50AM +0000, Winkler, Tomas wrote:
> 
> > 
> > On Tue, 2018-03-06 at 11:30 +0200, Tomas Winkler wrote:
> > > Factor out get random implementation from tpm-interface.c into
> > > tpm1_get_random function in tpm1-cmd.c.
> > > No functional changes.
> > >
> > > Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
> > 
> > While you are doing this, please make it use tpm_buf so tha we get stuff out
> > of that nasty union. Using "helper" structs is still fine, just move it right
> > before the function implementation out of tpm.h (there are examples of this
> > tpm2-cmd.c).
> 
> Sure, but not while moving code, this is dangerous. Should be done after code is moved.

Makes sense have use two steps here.

/Jarkko
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 6b70cefed505..59ca2e30b4d2 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -707,14 +707,6 @@  int tpm_pm_resume(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 
-#define TPM_ORD_GET_RANDOM 70
-#define TPM_GETRANDOM_RESULT_SIZE	18
-static const struct tpm_input_header tpm_getrandom_header = {
-	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
-	.length = cpu_to_be32(14),
-	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
-};
-
 /**
  * tpm_get_random() - get random bytes from the TPM's RNG
  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
@@ -725,57 +717,19 @@  static const struct tpm_input_header tpm_getrandom_header = {
  */
 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
 {
-	struct tpm_cmd_t tpm_cmd;
-	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
-	int err, total = 0, retries = 5;
-	u8 *dest = out;
-
-	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
-		return -EINVAL;
+	int err;
 
 	chip = tpm_chip_find_get(chip);
 	if (!chip)
 		return -ENODEV;
 
-	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
 		err = tpm2_get_random(chip, out, max);
-		tpm_put_ops(chip);
-		return err;
-	}
-
-	do {
-		tpm_cmd.header.in = tpm_getrandom_header;
-		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
-
-		err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
-				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
-				       offsetof(struct tpm_getrandom_out,
-						rng_data),
-				       0, "attempting get random");
-		if (err)
-			break;
-
-		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
-		if (recd > num_bytes) {
-			total = -EFAULT;
-			break;
-		}
-
-		rlength = be32_to_cpu(tpm_cmd.header.out.length);
-		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
-			      recd) {
-			total = -EFAULT;
-			break;
-		}
-		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
-
-		dest += recd;
-		total += recd;
-		num_bytes -= recd;
-	} while (retries-- && total < max);
+	else
+		err = tpm1_get_random(chip, out, max);
 
 	tpm_put_ops(chip);
-	return total ? total : -EIO;
+	return err;
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
 
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 1a8ef4d3cb1c..b5fe0269a833 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -537,6 +537,8 @@  int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
 		    const char *log_msg);
 ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 		    const char *desc, size_t min_cap_length);
+int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max);
+
 int tpm_pm_suspend(struct device *dev);
 int tpm_pm_resume(struct device *dev);
 
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
index 0e10a40b28b1..2c075a03a17a 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -472,3 +472,57 @@  ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 	return rc;
 }
 EXPORT_SYMBOL_GPL(tpm1_getcap);
+
+#define TPM_ORD_GET_RANDOM 70
+#define TPM_GETRANDOM_RESULT_SIZE	18
+static const struct tpm_input_header tpm_getrandom_header = {
+	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
+	.length = cpu_to_be32(14),
+	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
+};
+
+int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max)
+{
+	struct tpm_cmd_t tpm_cmd;
+	u32 recd;
+	u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
+	u32 rlength;
+	int err, total = 0, retries = 5;
+	u8 *dest = out;
+
+	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
+		return -EINVAL;
+
+	do {
+		tpm_cmd.header.in = tpm_getrandom_header;
+		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
+
+		err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
+				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
+				       offsetof(struct tpm_getrandom_out,
+						rng_data),
+				       0, "attempting get random");
+		if (err)
+			break;
+
+		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
+		if (recd > num_bytes) {
+			total = -EFAULT;
+			break;
+		}
+
+		rlength = be32_to_cpu(tpm_cmd.header.out.length);
+		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
+			      recd) {
+			total = -EFAULT;
+			break;
+		}
+		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
+
+		dest += recd;
+		total += recd;
+		num_bytes -= recd;
+	} while (retries-- && total < max);
+
+	return total ? total : -EIO;
+}